Confirmation for Simultaneous Transmission and Reception

Abstract

Methods for a communication device capable of simultaneous transmission and reception are disclosed. Among them, the first method is for receiving a packet including a header and a payload, and the second method is for transmitting a packet including a header and a payload. The second method includes transmitting at least a part of the header. The first method includes: receiving at least a part of the header; attempting to decode the part of the header; and (when the part of the header is successfully decoded) transmitting a header acknowledgment signal. The second method includes: monitoring the reception of the header acknowledgment signal; and (when it is detected that there is no header acknowledgment signal) interrupting the transmission of the packet and scheduling the packet for retransmission. Corresponding apparatuses, transceivers, communication devices, and computer program products are also disclosed.

Description

Technical Field

[0001] The present disclosure generally relates to the field of wireless communication. More specifically, the present invention relates to acknowledgments for simultaneous transmission and reception. Background Art

[0002] One challenge in wireless communication is the latency of the feedback mechanism. In particular, when adaptation depends on the information provided by the feedback mechanism, due to such latency, the adaptation of the communication setup may be delayed.

[0003] Examples of adaptation include the selection of modulation and coding schemes (MCS), retransmission decisions, interruption of ongoing transmissions, etc. Examples of feedback include acknowledgment signals (ACK), negative acknowledgment signals (NACK), channel quality indicators (CQI), channel state information (CSI), etc.

[0004] Therefore, an alternative feedback mechanism for wireless communication is needed. Preferably, such an alternative feedback mechanism should provide an improvement in the adaptation of the communication setup. For example, due to reduced feedback latency, such an alternative feedback mechanism may enable faster adaptation. Summary of the Invention

[0005] It should be emphasized that when used in this specification, the term "comprising" (which may be replaced by "including") is considered to specify the presence of stated features, integers, steps, or components, but does not preclude the presence or addition of one or more other features, integers, steps, components, or combinations thereof. As used herein, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0006] Generally, when an arrangement is mentioned herein, it is understood as a physical product; for example, a device. The physical product may include one or more parts, such as control circuitry in the form of one or more controllers, one or more processors, etc.

[0007] An object of some embodiments is to solve or alleviate, mitigate or eliminate at least some of the above or other drawbacks.

[0008] A first aspect is a method for a communication device capable of simultaneous transmission and reception, wherein the method is for receiving a packet including a header and a payload.

[0009] The method includes: receiving at least a part of the header; attempting to decode the part of the header; and (when the part of the header is successfully decoded) sending a header acknowledgment signal.

[0010] In some embodiments, the method further comprises: receiving the payload; attempting to decode the payload; and (when the payload is successfully decoded) sending a packet acknowledgement signal.

[0011] In some embodiments, sending the header acknowledgement signal is performed before receiving the payload or during the reception of the payload.

[0012] In some embodiments, the portion of the header includes a header field indicating the packet recipient address.

[0013] In some embodiments, the method further comprises: receiving the header in its entirety; and (when the header matches the previously received header of a previously received and successfully decoded packet) retransmitting the previously sent packet acknowledgement signal associated with the previously received and successfully decoded packet.

[0014] In some embodiments, the method further comprises: sending an indication of a recommended packet modulation and coding scheme together with the header acknowledgement signal.

[0015] In some embodiments, sending the header acknowledgement signal is performed using a more robust acknowledgement modulation and coding scheme than the currently applied packet modulation and coding scheme.

[0016] A second aspect is a method for a communication device capable of simultaneous transmission and reception, wherein the method is for transmitting a packet comprising a header and a payload.

[0017] The method comprises: transmitting at least a portion of the header; monitoring for the reception of a header acknowledgement signal; and (when it is detected that the header acknowledgement signal is absent) interrupting the transmission of the packet and scheduling the packet for retransmission.

[0018] In some embodiments, the method further comprises: transmitting the header in its entirety; monitoring for the reception of an early packet acknowledgement signal; and (when the early packet acknowledgement signal is detected) interrupting the transmission of the packet.

[0019] In some embodiments, the method further comprises: transmitting the payload; monitoring for the reception of a packet acknowledgement signal; and (when it is detected that the packet acknowledgement signal is absent) scheduling the packet for retransmission.

[0020] In some embodiments, detecting the absence of the packet acknowledgement signal includes detecting an explicit packet non-acknowledgement signal.

[0021] In some embodiments, the portion of the header includes a header field indicating the packet recipient address.

[0022] In some embodiments, the method further comprises: receiving an indication of a recommended packet modulation and coding scheme together with the header acknowledgement signal; and using the recommended packet modulation and coding scheme to transmit the packet immediately following.

[0023] A third aspect is a computer program product comprising a non-transitory computer-readable medium having stored thereon a computer program comprising program instructions. The computer program is loadable into a data processing unit and configured to cause the method according to any one of the first and second aspects to be performed when the computer program is run by the data processing unit.

[0024] A fourth aspect is a device for a communication device capable of simultaneous transmission and reception, wherein the device is for receiving a packet comprising a header and a payload.

[0025] The device comprises control circuitry configured to cause: receiving at least a portion of the header; attempting to decode the portion of the header; and (in response to successful decoding of the portion of the header) transmitting a header acknowledgement signal.

[0026] A fifth aspect is a device for a communication device capable of simultaneous transmission and reception, wherein the device is for transmitting a packet comprising a header and a payload.

[0027] The device comprises control circuitry configured to cause: transmitting at least a portion of the header; monitoring for receipt of a header acknowledgement signal; and (in response to detecting the absence of the header acknowledgement signal) interrupting transmission of the packet and scheduling the packet for retransmission.

[0028] A sixth aspect is a transceiver for a communication device, the transceiver comprising the device according to any one of the fourth and fifth aspects.

[0029] A seventh aspect is a communication device, the communication device comprising the transceiver according to the sixth aspect and / or the device according to any one of the fourth and fifth aspects.

[0030] In some embodiments, any of the above aspects may additionally have a feature that is the same as or corresponding to any one of the various features described above for any other aspect.

[0031] An advantage of some embodiments is to provide an alternative feedback mechanism for wireless communication.

[0032] Another advantage of some embodiments is that the alternative feedback mechanism provides an improvement in the adaptation of communication settings (such as one or more of the following: MCS selection, retransmission decision, and transmission interruption).

[0033] Another advantage of some embodiments is that due to reduced feedback latency, alternative feedback mechanisms enable faster adaptation. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Other objects, features, and advantages will be apparent from the following detailed description of embodiments with reference to the accompanying drawings. The drawings are not necessarily to scale, but rather focus on illustrating example embodiments.

[0035] Figure 1 is a schematic diagram showing a grouping according to some embodiments;

[0036] Figure 2 is a schematic diagram showing various signaling scenarios according to some embodiments;

[0037] Figure 3 is a combined flowchart and signaling diagram showing example method steps and signaling according to some embodiments;

[0038] Figure 4 is a schematic block diagram showing an example arrangement (device) according to some embodiments;

[0039] Figure 5 is a schematic block diagram showing an example arrangement (device) according to some embodiments; and

[0040] Figure 6 is a schematic diagram showing an example computer-readable medium according to some embodiments. DETAILED DESCRIPTION

[0041] As already mentioned above, it should be emphasized that when used in this specification, the term "comprising" (which may be replaced by "including") is considered to specify the presence of the stated features, integers, steps, or components, but does not preclude the presence or addition of one or more other features, integers, steps, components, or combinations thereof. As used herein, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise.

[0042] Embodiments of the present disclosure will be described and illustrated more fully hereinafter with reference to the accompanying drawings. However, the solutions disclosed herein may be implemented in many different forms and should not be construed as limited to the embodiments set forth herein.

[0043] Various examples of some embodiments will be given below in the context of IEEE 802.11. It should be noted that these examples are not intended to be limiting. On the contrary, they are merely illustrative. Thus, the problems and embodiments may equally apply to any scenario with communication devices capable of simultaneous transmission and reception. As used herein, a communication device capable of simultaneous transmission and reception may be defined as a communication device configured to perform simultaneous transmission and reception.

[0044] Embodiments will now be described in which alternative feedback mechanisms for wireless communication are provided. These mechanisms are for communication devices capable of transmitting and receiving simultaneously. Examples of scenarios for simultaneous transmission and reception include full-duplex communication scenarios, frequency-division duplex (FDD) scenarios, and the like.

[0045] The communication device can be, for example, a wireless communication device (such as a user equipment UE or a station STA) or a network node (such as a base station BS, a Node B, an evolved Node B, or an access point AP).

[0046] The alternative feedback mechanisms for wireless communication provided herein are for the communication of one or more packets, where each packet includes a header and a payload. In some contexts, a packet can also be represented as a frame.

[0047] Figure 1 An example of such a packet according to some embodiments is schematically shown. Example packet 100 includes a header (HEAD) 140 and a payload (PL) 160. For various purposes, the header can be subdivided into two or more header fields. This is illustrated in Figure 1 where header 140 includes a receiver indicator field (RI) 145. The receiver indicator can be, for example, a receiver address.

[0048] The packet can also include one or more other components, which are illustrated in Figure 1 by a preamble (PA) 120 and an error detection component (ED) 180. The error detection component can include, for example, a cyclic redundancy check (CRC) or a frame check sequence (FCS).

[0049] When the wireless communication is according to the IEEE 802.11 standard (such as the IEEE 802.11n standard), example packet 100 can include a physical (PHY) layer preamble 120 and a medium access control (MAC) protocol data unit (MPDU), where the MPDU itself includes an MPDU header 140, an MPDU payload 160, and an FCS 180.

[0050] A typical MPDU header 140 can include a frame control field (two octets), a duration / ID (ID) field (two octets), a first address field (six octets) carrying the receiver address, a second address field (six octets), a third address field (six octets), a sequence control field (two octets), a fourth address field (six octets), a quality of service (QoS) control field (two octets), and a high throughput (HT) control field (four octets).

[0051] The frame control field includes information about the MPDU type. Depending on the type of MPDU, one or more header fields may be absent. However, the first address field carrying the receiver address is typically always present in the current IEEE 802.11 MPDU packet.

[0052] Since the first address field of the MPDU is relatively large (six octets, i.e., 48 bits), the error probability of converting the first address field to an address matching another receiver is relatively small.

[0053] It should also be noted that the first address field appears early in the MPDU and early in the MPDU header (before any optional header fields). Therefore, the duration from the start of the packet to the end of the first address field is determined (although typically depending on the applied modulation and coding scheme MCS).

[0054] In IEEE 802.11, there is an activity regarding simultaneous transmit and receive (STR), which is commonly referred to as full-duplex (FD) technology. In IEEE, STR may use the same frequency band simultaneously in both the uplink (UL) and downlink (DL). Therefore, full-duplex has not been standardized by IEEE 802.11 yet, but the work is in progress.

[0055] A simple extension of the existing packet ACK method for half-duplex in IEEE 802.11 can be implemented such that the transmitter-side communication device monitors the reception of the packet ACK during a period after the packet has been completely transmitted (as in a half-duplex scenario), where this monitoring is performed immediately after sending the packet (due to the full-duplex capability) when the transmitter is free to start other activities (such as sending the next packet).

[0056] As mentioned above, a challenge in wireless communication is the delay of the feedback mechanism, which may lead to a delayed adaptation of the communication setup. Some embodiments alleviate this problem by leveraging the ability of simultaneous transmit and receive.

[0057] When coding is performed without time interleaving (as in IEEE 802.11), the decoding of a packet (such as an MPDU) can start immediately, even before the entire packet is received. Therefore, under the assumption that the packet will be correctly decoded, the information in the header is available before the payload is decoded. Without error detection for the header, it is not known whether the header is correctly decoded until the decoder has decoded the entire packet.

[0058] Considering the receiver indicator field 145, two types of errors can occur from the perspective of the receiver; missed detection and false alarm. For missed detection (where a packet that should be received is considered to be intended for another receiver), the packet will be considered lost and will be retransmitted. For false alarm (where a packet intended for another receiver is processed as a whole), when the entire packet is decoded, packet error detection will notice the error. The occurrence of missed detection can be on the same order of magnitude as the packet error rate, while if the address space is large, false alarms will generally occur with a negligible probability. For example, if the length of the address field is 48 bits, the probability of false alarm is approximately Therefore, when the receiver indicator field of the packet header indicates the receiver address of the communication device, it can be safe for the communication device to assume that the packet is intended for the communication device.

[0059] By taking advantage of the ability to send and receive simultaneously, a scheme for separate acknowledgment of the header (or a part of the header) can be considered, as Figure 2 will be illustrated.

[0060] Figure 2 Schematically shows various signaling scenarios (a - f) according to some embodiments, where the ability to send and receive simultaneously is utilized to reduce the latency of the feedback mechanism.

[0061] Generally, the upper part of each scenario diagram represents the activities of a first communication device, which is configured to send (TX) a packet including a header (240) and a payload (260), and receive (RX) feedback associated with the packet, while the lower part of each scenario diagram represents the activities of a second communication device, which is configured to receive (RX) a packet including a header (241) and a payload (261), and send (TX) feedback associated with the packet.

[0062] Scenario (a) shows the principle of a method where the ability to send and receive simultaneously is utilized to reduce the latency of the feedback mechanism. The initiation of packet transmission is shown by the left - most downward arrow.

[0063] When the second communication device has received at least a part of the header (241, compared to Figure 1 140), it attempts to decode that part of the header. Generally, that part of the header includes a header field indicating the packet receiver address (compared to Figure 1 145). However, it is not excluded that that part of the header can additionally or alternatively include other information that enables determination of whether the header should be considered (correctly) received. Examples of such other information include an error - detection field for the header.

[0064] When that part of the header is successfully decoded, the second communication device sends a header acknowledgment signal (H - ACK) 250. FromFigure 1 As can be seen in scenario (a), it is possible to send an H-ACK while the reception of a packet (e.g., the reception of the remainder of header 241 and / or payload 261) is still ongoing because the second communication device is capable of sending and receiving simultaneously.

[0065] It is possible for the first communication device to receive an H-ACK 251 while the transmission of a packet (e.g., the transmission of the remainder of header 240 and / or payload 260) is still ongoing because the first communication device is capable of sending and receiving simultaneously.

[0066] When the second communication device has received the payload (261, compared to Figure 1 160 of), it attempts to decode the payload. When the payload is successfully decoded, the second communication device sends a packet acknowledgment signal (P-ACK) 270. It is possible to send a P-ACK while the reception (e.g., of the next packet) is ongoing because the second communication device is capable of sending and receiving simultaneously. It is possible for the first communication device to receive a P-ACK 271 while the transmission (e.g., of the next packet) is ongoing because the first communication device is capable of sending and receiving simultaneously.

[0067] Scenario (b) shows a situation where this part of the header is not successfully decoded. The unsuccessful decoding of this part of the header can, for example, include determining that the receiver indicator field (compared to Figure 1 145 of) does not indicate the second communication device as the intended receiver of the packet. For example, this can occur due to an error in the receiver indicator field or because the packet is intended for another communication device.

[0068] When this part of the header is not successfully decoded, the second communication device does not send any H-ACK, as can be seen in scenario (b). If the packet is intended for the second communication device, the first communication device will not receive any H-ACK during the monitoring period 252 (i.e., it detects the absence of an H-ACK; implicit H-NACK). Then, the first communication device can interrupt (abort) the transmission of the packet, as shown by the shortened payload 260 in scenario (b), and schedule the packet for retransmission.

[0069] Thus, it is indicated early that the packet will not be correctly received. By adapting this early indication, unnecessary transmissions are reduced.

[0070] Scenario (c) shows the following situation: where that part of the header has been successfully decoded, but the first communication device does not (correctly) receive an H-ACK. Thus, while the reception of the packet (e.g., the rest of header 241 and / or the payload 261) is still in progress, the second communication device sends an H-ACK 250, but the first communication device will not receive any H-ACK during the monitoring period 252 (i.e., it detects the absence of an H-ACK; implicit H-NACK). Then, the first communication device can interrupt (abort) the transmission of the packet, as shown by the shortened payloads 260, 261 in scenario (c), and schedule the packet for retransmission.

[0071] Thus, in this scenario, even if the packet may have been correctly received, the packet transmission is interrupted.

[0072] Scenario (d) shows the situation where the payload is not successfully decoded. The unsuccessful decoding of the payload can include, for example, determining that the error detection component (compared to Figure 1 180 of

[0073] indicates that the payload contains an error. When the payload is not successfully decoded, the second communication device does not send any P-ACK, as can be seen in scenario (d), and the first communication device will not receive any P-ACK during the monitoring period 272 (i.e., it detects the absence of a P-ACK; implicit P-NACK). In some embodiments, the second communication device sends a P-NACK in scenario (d), and the first communication device will receive a P-NACK during the monitoring period 272 (i.e., it detects the absence of a P-ACK; explicit P-NACK). In either case, when the absence of a P-ACK is detected, the first communication device can schedule the packet for retransmission.

[0074] Scenario (e) shows the following situation: where the payload is successfully decoded, but the first communication device does not (correctly) receive a P-ACK. Thus, the second communication device sends a P-ACK 270, but the first communication device will not receive any P-ACK during the monitoring period 272 (i.e., it detects the absence of a P-ACK; implicit P-NACK). Then, the first communication device can schedule the packet for retransmission.

[0075] Thus, in this scenario, even if the packet has been correctly received, the packet is scheduled for retransmission. Methods for mitigating this drawback will be described in connection with Figure 3 explanation.

[0076] Scenario (f) shows the following situation: where the payload is successfully decoded and the first communication device correctly receives the P-ACK. Thus, the second communication device sends P-ACK 273, and the first communication device receives P-ACK 274 during the monitoring period. Then, the first communication device can determine that the packet has been successfully sent.

[0077] Figure 3 is a combined flowchart and signaling diagram showing example method steps and signaling according to some embodiments. Figure 3 The left half shows the method steps of a first communication device (capable of transmitting and receiving simultaneously) for transmitting packets 310, 390 including headers (HEAD) 140, 240, 241, 311, 351 and payloads (PL) 160, 260, 261, 313, 353. Figure 3 The right half shows the method steps of a second communication device (capable of transmitting and receiving simultaneously) for receiving packets 350 including headers (HEAD) 140, 240, 241, 311, 351 and payloads (PL) 160, 260, 261, 313, 353.

[0078] When at least a part (PT) of the header 312, 352 has been sent by the first communication device and received by the second communication device, the second communication device attempts to decode this part of the header, as shown by step 365.

[0079] The design principle in IEEE 802.11 is not to perform interleaving over multiple orthogonal frequency division multiplexing (OFDM) symbols. Thus, the decoder can start decoding immediately upon receiving a symbol. As a result, the information encapsulated earlier in the packet is also decoded earlier. However, according to the prior art, the receiver does not know whether the entire packet has been correctly decoded until it can compare the data with the frame check sequence (FCS).

[0080] When this part of the header is successfully decoded (the "yes" path in step 366; compared with Figure 2 scenarios c-f of Figure 1 ), the second communication device sends a header acknowledgment signal (H-ACK), as shown by step 367 and signal 391, and continues to receive and decode the packet. The successful decoding of this part of the header can, for example, include determining that the receiver indicator field (compared with

[0081] 145 of Figure 2Compared with scenario b), the second communication device stops receiving (and decoding) the packet, as shown by step 368. Therefore, in this case, no H-ACK is sent. The unsuccessful decoding of this part of the header can include, for example, determining that the receiver indicator field (compared with Figure 1 145 of) does not indicate the second communication device as the intended receiver of the packet. Alternatively or additionally, the unsuccessful decoding of this part of the header can include, for example, determining that the error detection part of the header indicates an error in the reception and decoding of this part.

[0082] Generally, attempting to decode this part of the header is directly in response to the reception of this part of the header and / or the sending of H-ACK is directly in response to the successful decoding of this part of the header.

[0083] As mentioned above, the sending of H-ACK can be simultaneous with the continuous reception of the second communication device (e.g., before or during the reception of the payload). One or more of steps 365 and 367 can be performed during the reception of the rest of the header. Alternatively or additionally, one or more of steps 365 and 367 can be performed during the reception of the payload. A duration can be specified for the second communication device to start when receiving this part of the header, and the H-ACK should be sent within this duration. Alternatively or additionally, a duration (monitoring period) can be specified for the first communication device to start when sending this part of the header, and the H-ACK should be received within this duration.

[0084] When at least a part (PT) 312, 365 of the header has been sent by the first communication device, the first communication device monitors the reception of H-ACK, as shown by step 325. This step generally includes monitoring the reception of H-ACK within the specified monitoring period as described above.

[0085] When an H-ACK is received (the "yes" path in step 326; compared with Figure 2 scenarios d-f; H-ACK is detected), the first communication device continues to send the packet. When no H-ACK is received (the "no" path in step 326; compared with Figure 2 scenarios b-c; no H-ACK is detected), the first communication device interrupts (stops / cancels / aborts) the sending of the packet, as shown by step 368, and schedules the packet for retransmission, as shown by step 349.

[0086] As mentioned above, the monitoring and reception of H-ACK can be simultaneous with the continuous sending of the first communication device. One or more of steps 325 and 326 can be performed during the sending of the rest of the header. Alternatively or additionally, one or more of steps 325 and 326 can be performed during the sending of the payload.

[0087] Typically, the transmission of the header confirmation signal can be performed using a more robust confirmation modulation and coding scheme than the packet modulation and coding scheme currently applied. In this context, a more robust modulation and coding scheme can refer to a modulation and coding scheme that achieves a lower error probability (e.g., by using one or more of the following: lower rate coding, lower order modulation, and shorter information packets). This makes Figure 2 Scenario (c) of Figure 2 less likely to occur. A similar approach can be used for the P-ACK to make

[0088] Alternatively or additionally, by applying steps 376, 377, 379, 337, 338, 339, the disadvantages described above in connection with Figure 2 Scenario (e) (even if the packet has been correctly received, the packet can be scheduled for retransmission because the first communication device did not correctly receive the P-ACK) can be mitigated. It should be noted that these steps are optional with respect to the other steps described in connection with Figure 3 For example, according to some embodiments, steps 337, 338, 339 may be only related to packet retransmission.

[0089] When the header has been sent by the first communication device and has been received in its entirety by the second communication device, the second communication device checks whether the header matches the previously received header of a previously received and successfully decoded packet, as shown by step 376.

[0090] In some embodiments, this can be achieved by utilizing the error detection portion of the header (e.g., the header CRC or the header FCS). For example, if the error detection portion of the header indicates error-free reception and decoding of the header, and if the header is the same as the header of a previously received and successfully decoded packet (possibly differing in some value indicating the number of transmission attempts of the packet and / or some value indicating the time resources used for transmission), then a match can be detected.

[0091] When the header matches the previously received header of a previously received and successfully decoded packet (the "yes" path in step 376), the second communication device retransmits the previously sent packet acknowledgment signal (P-ACK) associated with the previously received and successfully decoded packet, as shown by step 377 and signal 392, and stops receiving the packet (since the packet has been correctly received). Alternatively or additionally, the second communication device can notify the first communication device in any suitable way other than retransmitting the previously sent P-ACK that the packet has been correctly received previously.

[0092] When the header does not match any previously received header of a previously received and successfully decoded packet (the "No" path in step 376), the second communication device continues to receive and decode the packet.

[0093] A duration can be specified for the second communication device to start when receiving the header, within which the previously sent P-ACK should be sent. Alternatively or additionally, a duration (monitoring period) can be specified for the first communication device to start when sending the header, within which a premature P-ACK should be received.

[0094] When the first communication device has sent the header, the first communication device monitors the receipt of a premature P-ACK, as shown by step 337. This step generally includes monitoring the receipt of a premature P-ACK within the specified monitoring period as described above.

[0095] When a premature P-ACK is received (the "Yes" path in step 338; a premature P-ACK is detected), the first communication device interrupts (stops / cancels / aborts) the transmission of the packet, as shown in step 339, and considers the packet to have been successfully sent, as shown by step 348. When a premature P-ACK is not received (the "No" path in step 338; no premature P-ACK is detected), the first communication device continues the transmission of the packet.

[0096] The monitoring and receipt of a premature P-ACK can be simultaneous with the continuous transmission of the first communication device. One or more of steps 337 and 338 can be performed during the transmission of the payload.

[0097] When the payloads 160, 313, 353 have been sent by the first communication device and received by the second communication device, the second communication device attempts to decode the payload, as shown in step 385.

[0098] When the payload is successfully decoded (the "Yes" path in step 386; compared with the scenario e-f of Figure 2 ), the second communication device sends a packet acknowledgment signal (P-ACK), as shown by steps 387 and signal 393. The successful decoding of the packet can include, for example, determining that the error detection portion (e.g., CRC or FCS) 180 indicates error-free reception and decoding.

[0099] According to various embodiments, when the payload is not successfully decoded (the "No" path in step 386; compared with the scenario d of Figure 2 ), the second communication device can either perform no operation or send an explicit packet negative acknowledgment signal (P-NACK), as shown by step 388. The unsuccessful decoding of the packet can include, for example, determining that the error detection portion (e.g., CRC or FCS) 180 indicates an error in reception and decoding.

[0100] The transmission of P-ACK and / or P-NACK can be simultaneous with the continuous reception (e.g., reception of the next packet) of the second communication device. During such continuous reception, one or more of steps 385, 386, 387, and 388 can be performed. A duration starting upon reception of the payload can be specified for the second communication device, within which the P-ACK or P-NACK should be transmitted. Alternatively or additionally, a duration (monitoring period) starting upon transmission of the payload can be specified for the first communication device, within which the P-ACK or P-NACK should be received.

[0101] When the first communication device has transmitted the payload 160, 313, 353, the first communication device monitors the reception of the P-ACK, as shown by step 345. This step generally includes monitoring the reception of the P-ACK within the specified monitoring period as described above.

[0102] When the P-ACK is received (the "yes" path in step 346; compared with Figure 2 scenario f; detecting the P-ACK), the first communication device considers the packet to have been successfully transmitted, as shown by step 348. When the P-ACK is not received (the "no" path in step 346; compared with Figure 2 scenarios d - e; detecting the absence of the P-ACK), the first communication device schedules the packet for retransmission, as shown by step 349. The situation of not receiving the P-ACK can include not receiving any signal during the monitoring step 345, or can include receiving an explicit P-NACK sent as in step 388 (i.e., detecting the absence of the P-ACK can include detecting the explicit P-NACK).

[0103] As described above, the monitoring and reception of P-ACK and / or P-NACK can be simultaneous with the continuous transmission of the first communication device. During such continuous transmission, one or more of steps 345, 346, 349, and 348 can be performed.

[0104] Generally, the monitoring period can be statically determined in advance, or can be semi-static or dynamic. Details of the monitoring period can be signaled, for example, from the second communication device to the first communication device, or can be determined by the first communication device based on measurements of the round-trip time (including decoding). Example monitoring periods can be within the interval of 0.5 - 5.0 microseconds, such as 0.8, 1.6, or 4.0 microseconds.

[0105] Generally, the packet acknowledgment signal (P-ACK) can be regarded as an acknowledgment signal for the entire packet or for only a part of the packet (e.g., the payload; it can then be called the payload acknowledgment signal).

[0106] In some embodiments, an indication of a recommended modulation and coding scheme (MCS) (e.g., CQI or CSI) may be sent together with the H-ACK. When a first communication device receives the H-ACK, the recommended modulation and coding scheme may be used to send the packet immediately following. This enables faster MCS adaptation than if the indication were received after the entire packet had been sent (in which case the recommended modulation and coding scheme could not be used to send the packet immediately following because the transmission of such a packet has already started).

[0107] For example, in IEEE 802.11, there is a mechanism called MCS feedback. Starting from 802.11n, there is an HT control field in the header that contains an MCS recommendation. A second communication device monitors the quality of the received transmission and provides feedback to the transmitter regarding the best MCS selection. Including this MCS recommendation in the H-ACK transmission improves the MCS adaptation speed.

[0108] In some embodiments, the method described in Figure 3 may be dynamically enabled / disabled. For example, a first communication device and a second communication device may notify each other whether they are capable of simultaneous transmission and reception (and / or for other reasons, whether they are capable of using the H-ACK method), and the method described in Figure 3 may be enabled only if both the first communication device and the second communication device are capable of, for example, simultaneous transmission and reception. For example, a single bit may be used to signal this capability. One possibility is to use a single bit in the PHY signal (SIG) field (in the PHY header or preamble). Alternatively or additionally, the enabling / disabling may be based on the need of either the first communication device or the second communication device to apply the H-ACK method. Such a need may also be signaled appropriately between the first communication device and the second communication device.

[0109] Starting from IEEE 802.11ac, it has been common practice to use aggregated MPDUs for data transmission. Although the need for aggregated MPDUs (A-MPDUs) (where several MAC layer packets are collected into one PHY layer packet) is significantly reduced when the system has FD capabilities (because the overhead of waiting for ACKs is eliminated and because no inter-frame space (IFS) overhead is required), it is noted that the methods described herein may equally apply to A-MPDUs. Each MAC layer packet may then be associated with a corresponding H-ACK (and a corresponding P-ACK). A-MPDUs still have some advantages, such as the ability to eliminate preamble and signal (SIG) field overhead because the preamble can be reduced to a single SIG field (i.e., aggregated physical layer convergence procedure PCLP service data unit A-PSDU encapsulation).

[0110] Figure 4 and 5 schematically illustrates an example apparatus for a transceiver and / or communication device capable of simultaneous transmission and reception according to some embodiments. The communication device may be, for example, a wireless communication device (such as a user equipment UE or a station STA) or a network node (such as a base station BS, a Node B, an evolved Node B, or an access point AP).

[0111] Figure 4 Illustrates an example apparatus 410 for receiving a packet including a header and a payload. The apparatus includes control circuitry (CNTR; such as a controller or a control module) 400. The control circuitry may be adapted to cause the execution of Figure 3 one or more steps of the right half of

[0112] The control circuitry is configured to cause the reception of at least a part of the header, the entire header, and the payload. To this end, the control circuitry may be associated with (e.g., (operatively) connectable or connected to) a receiving circuit (such as a receiver or a receiving module; shown as part of the transceiver circuit TX / RX in Figure 4 ) 430. The receiving circuit may be configured to receive at least a part of the header, the entire header, and the payload.

[0113] The control circuitry is further configured to cause an attempt to decode a part of the header (compared to step 365 of Figure 3 ), the entire header (compared to step 376 of Figure 3 ), and the payload (compared to step 385 of Figure 3 ). To this end, the control circuitry may include a decoding circuit (DEC; such as a decoder or a decoding module) 401, or otherwise be associated with (e.g., (operatively) connectable or connected to) the decoding circuit 401. The decoding circuit may be configured to attempt to decode a part of the header, the entire header, and the payload.

[0114] The control circuitry is further configured to cause the transmission of a header acknowledgment signal in response to a part of the header being successfully decoded (compared to step 367 of Figure 3 ).

[0115] The control circuitry may further be configured to cause the retransmission of a previously transmitted packet acknowledgment signal associated with a previously received and successfully decoded packet in response to the header matching a previously received header of a previously received and successfully decoded packet (compared to step 377 of Figure 3 ).

[0116] The control circuitry may further be configured to cause the transmission of a packet acknowledgment signal in response to the payload being successfully decoded (compared to Figure 3compared to step 387 of

[0117] To this end, the control circuit can be associated with (e.g., (operatively) connectable or connected to) a transmission circuit (such as a transmitter or transmission module; shown as part of transceiver circuit TX / RX in Figure 4 ) 430. The transmission circuit can be configured to transmit a header acknowledgment signal and a packet acknowledgment signal, and retransmit a previously transmitted packet acknowledgment signal.

[0118] Figure 5 An example apparatus 510 for transmitting a packet including a header and a payload is shown. The apparatus includes a control circuit (CNTR; such as a controller or control module) 500. The control circuit can be adapted to cause one or more steps of Figure 3 the left half of

[0119] to be performed. The control circuit is configured to cause at least a portion of the header, the entire header, and the payload to be transmitted. To this end, the control circuit can be associated with (e.g., (operatively) connectable or connected to) a transmission circuit (such as a transmitter or transmission module; shown as part of transceiver circuit TX / RX in Figure 5 ) 530. The transmission circuit can be configured to transmit at least a portion of the header, the entire header, and the payload.

[0120] The control circuit can also be configured to cause the reception of a header acknowledgment signal (compared to step 325 of Figure 3 ), a premature packet acknowledgment signal (compared to step 337 of Figure 3 ), and a packet acknowledgment signal (compared to step 345 of Figure 3 ) to be monitored. To this end, the control circuit can include a monitoring circuit (MON; such as a monitor or monitoring module) 501, or otherwise be associated with (e.g., (operatively) connectable or connected to) the monitoring circuit 501. The monitoring circuit can be configured to monitor the reception of the header acknowledgment signal, the premature packet acknowledgment signal, and the packet acknowledgment signal.

[0121] The control circuit is also configured to cause the transmission of a packet to be interrupted and the packet to be scheduled for retransmission in response to detecting the absence of a header acknowledgment signal (compared to steps 368 and 349 of Figure 3 ).

[0122] The control circuit can also be configured to cause the transmission of a packet to be interrupted in response to detecting a premature packet acknowledgment signal (compared to step 339 of Figure 3 ).

[0123] The control circuit can also be configured to cause a packet to be scheduled for retransmission in response to detecting the absence of a packet acknowledgment signal (compared toFigure 3 compared with step 349).

[0124] To this end, the control circuit may be associated with a scheduling circuit (SCH, such as a scheduler or a scheduling module) 502 (e.g., (operatively) connectable or connected to the scheduling circuit 502). The scheduling circuit may be configured to interrupt the transmission of packets and schedule packets for retransmission.

[0125] As described above, advantages of some embodiments include: providing an alternative feedback mechanism for wireless communication; the alternative feedback mechanism provides improvements in adapting communication settings (e.g., one or more of the following: MCS selection, retransmission decision, and transmission interruption); and due to reduced feedback latency, the alternative feedback mechanism enables faster adaptation.

[0126] By early stopping packets that are erroneously transmitted, time efficiency can be improved. The application of some embodiments enables early (before the entire packet is transmitted) stopping / interruption of transmission when this part of the header is not successfully decoded. Simulations show that the overall rate is improved by such an approach.

[0127] The speed of rate adaptation can also be improved by faster MCS feedback. In the prior art, MCS feedback can only be sent earliest together with the ACK of the complete packet. If the next packet from the transmitter is scheduled to be sent immediately after the confirmed complete packet, the transmitter may not have time to re-encode the next packet to adapt to the MCS feedback. However, by applying some embodiments, the MCS feedback arrives together with the H-ACK, which is typically before the coding of the next packet has started. Therefore, the speed of rate adaptation can be improved by at least one packet.

[0128] Generally, when an arrangement is mentioned herein, it is understood as a physical product; e.g., a device. The physical product may include one or more components, such as a control circuit in the form of one or more controllers, one or more processors, etc.

[0129] The described embodiments and their equivalents may be implemented in software or hardware or a combination thereof. The embodiments may be executed by a general-purpose circuit. Examples of general-purpose circuits include digital signal processors (DSPs), central processing units (CPUs), coprocessor units, field-programmable gate arrays (FPGAs), and other programmable hardware. Alternatively or additionally, the embodiments may be executed by a dedicated circuit (e.g., an application-specific integrated circuit (ASIC)). The general-purpose circuit and / or the dedicated circuit may be associated with or included in a device, such as a wireless communication device (e.g., a user equipment UE or a station STA) or a network node (e.g., a base station BS, a Node B, an evolved Node B, or an access point AP).

[0130] Embodiments may be present within an electronic device (such as a wireless communication device or a network node) comprising an arrangement, circuitry, and / or logic according to any of the embodiments described herein. Alternatively or additionally, an electronic device (such as a wireless communication device or a network node) may be configured to perform a method according to any of the embodiments described herein.

[0131] According to some embodiments, a computer program product comprises a computer-readable medium, such as a Universal Serial Bus (USB) memory, a plug-in card, an embedded drive, or a Read-Only Memory (ROM). Figure 6 An example computer-readable medium in the form of a Compact Disc (CD) ROM 600 is shown. The computer-readable medium has stored thereon a computer program comprising program instructions. The computer program may be loaded into a data processor (PROC) 620, which may be included, for example, in a wireless communication device or a network node 610. When loaded into the data processing unit, the computer program may be stored in a memory (MEM) 630, which is associated with or included in the data processing unit. According to some embodiments, when loaded into and run by the data processing unit, the computer program may cause the method steps according to any of the methods shown or otherwise described herein to be performed. Figure 3 The method steps according to any of the methods shown or otherwise described herein.

[0132] In general, all terms used herein will be interpreted according to their ordinary meaning in the relevant technical field, unless a different meaning is clearly given and / or implied in the context in which the term is used.

[0133] Various embodiments have been referred to herein. However, those skilled in the art will recognize that many variations of the described embodiments will still fall within the scope of the claims.

[0134] For example, the method embodiments described herein disclose example methods by steps to be performed in a particular order. However, it will be recognized that these sequences of events may occur in another order without departing from the scope of the claims. In addition, some method steps may be performed in parallel, even though they have been described as being performed in sequence. Thus, unless a step is explicitly described as being after or before another step and / or implicitly a step must be after or before another step, the steps of any method disclosed herein need not be performed in the exact order disclosed.

[0135] In the same way, it should be noted that in the description of the embodiments, the partitioning of functional blocks into specific units is by no means restrictive. On the contrary, these partitions are merely examples. A functional block described herein as a single unit may be divided into two or more units. Additionally, functional blocks described herein as being implemented as two or more units may be combined into fewer (e.g., a single) unit.

[0136] In appropriate circumstances, any feature of any embodiment disclosed herein may be applied to any other embodiment. Similarly, any advantage of any embodiment may apply to any other embodiment, and vice versa.

[0137] Accordingly, it should be understood that the details of the described embodiments are merely examples presented for illustrative purposes, and all variations falling within the scope of the claims are intended to be included therein.

Claims

1. A method for a communication device capable of simultaneous transmission and reception, wherein, the method is for receiving a packet including a header and a payload, and the method comprises: receiving at least a part of the header; attempting to decode the part of the header; when the part of the header is successfully decoded, sending a header acknowledgement signal while the reception of the packet is still in progress; and when the part of the header is not successfully decoded, stopping the reception and decoding of the packet.

2. The method according to claim 1, further comprising: receiving the payload; attempting to decode the payload; and when the payload is successfully decoded, sending a packet acknowledgement signal.

3. The method according to claim 1, wherein, sending the header acknowledgement signal is performed before receiving the payload or during the reception of the payload.

4. The method according to claim 1, wherein, the part of the header includes a header field indicating the packet recipient address.

5. The method according to any one of claims 1 to 4, further comprising: receiving the whole header; and when the header matches the previously received header of a previously received and successfully decoded packet, retransmitting the previously sent packet acknowledgement signal associated with the previously received and successfully decoded packet.

6. The method according to any one of claims 1 to 4, further comprising: sending an indication of a recommended packet modulation and coding scheme together with the header acknowledgement signal.

7. The method according to any one of claims 1 to 4, wherein, sending the header acknowledgement signal is performed using a more robust acknowledgement modulation and coding scheme than the currently applied packet modulation and coding scheme.

8. A method for a communication device capable of simultaneous transmission and reception, wherein, the method is for sending a packet including a header and a payload, and the method comprises: sending at least a part of the header; monitoring the reception of a header acknowledgement signal while the transmission of the packet is still in progress; when it is detected that there is no header acknowledgement signal, interrupting the transmission of the packet and scheduling the packet for retransmission; and when a header acknowledgement signal is received and includes an indication of a recommended packet modulation and coding scheme, using the recommended packet modulation and coding scheme to send the immediately following packet.

9. The method according to claim 8, further comprising: sending the whole header; monitoring the reception of a premature packet acknowledgement signal; and when it is detected that the premature packet acknowledgement signal, interrupting the transmission of the packet.

10. The method according to claim 8, further comprising: sending the payload; monitoring the reception of a packet acknowledgement signal; and when it is detected that there is no packet acknowledgement signal, scheduling the packet for retransmission.

11. The method according to claim 10, wherein, detecting that there is no packet acknowledgement signal includes detecting an explicit packet non-acknowledgement signal.

12. The method according to claim 8, wherein, the part of the header includes a header field indicating the packet recipient address.

13. A non-transitory computer-readable medium storing a computer program including program instructions, the computer program being loadable into a data processing unit and configured to cause the method according to any one of claims 1 to 12 to be executed when the computer program is run by the data processing unit.

14. An apparatus for a communication device capable of simultaneous transmission and reception, wherein, the apparatus is for receiving a packet including a header and a payload, the apparatus including control circuitry configured to cause: receiving at least a portion of the header; attempting to decode the portion of the header; in response to the portion of the header being successfully decoded, sending a header acknowledgement signal while reception of the packet is still in progress; and when the portion of the header is not successfully decoded, stopping reception and decoding of the packet.

15. The apparatus according to claim 14, wherein, the control circuitry is further configured to cause: receiving the payload; attempting to decode the payload; and in response to the payload being successfully decoded, sending a packet acknowledgement signal.

16. The apparatus according to claim 14, wherein, the control circuitry is configured to cause: the sending of the header acknowledgement signal to be performed before or during reception of the payload.

17. The apparatus according to claim 14, wherein, the portion of the header includes a header field indicating the packet recipient address.

18. The apparatus according to any one of claims 14 to 17, wherein, the control circuitry is further configured to cause: receiving the entire header; and in response to the header matching a previously received header of a previously received and successfully decoded packet, retransmitting a previously sent packet acknowledgement signal associated with the previously received and successfully decoded packet.

19. The apparatus according to any one of claims 14 to 17, wherein, the control circuitry is further configured to cause: an indication of a recommended packet modulation and coding scheme to be sent together with the header acknowledgement signal.

20. The apparatus according to any one of claims 14 to 17, wherein, the control circuitry is further configured to cause: the sending of the header acknowledgement signal to be performed using a more robust acknowledgement modulation and coding scheme than the currently applied packet modulation and coding scheme.

21. An apparatus for a communication device capable of simultaneous transmission and reception, wherein, the apparatus is for sending a packet including a header and a payload, the apparatus including control circuitry configured to cause: sending at least a portion of the header; monitoring for reception of a header acknowledgement signal while transmission of the packet is still in progress; in response to detecting the absence of the header acknowledgement signal, interrupting transmission of the packet and scheduling the packet for retransmission; and when a header acknowledgement signal is received and includes an indication of a recommended packet modulation and coding scheme, using the recommended packet modulation and coding scheme to send subsequent packets.

22. The apparatus according to claim 21, wherein, the control circuitry is further configured to cause: Transmit the entire header; Monitor the reception of premature packet acknowledgment signals; and In response to detecting the premature packet acknowledgment signal, interrupt the transmission of the packet.

23. The apparatus according to claim 21, wherein, the control circuit is further configured to cause: Transmit the payload; Monitor the reception of packet acknowledgment signals; and In response to detecting the absence of the packet acknowledgment signal, schedule the packet for retransmission.

24. The apparatus according to claim 23, wherein, detecting the absence of the packet acknowledgment signal includes detecting an explicit packet non-acknowledgment signal.

25. The apparatus according to claim 21, wherein, the portion of the header includes a header field indicating the packet recipient address.

26. A transceiver for a communication device, the transceiver comprising the apparatus according to any one of claims 14 to 25.

27. A communication device, comprising the transceiver according to claim 26 or the apparatus according to any one of claims 14 to 25.

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